Restriction of hazardous substances by statutes such as the Directive on the Restriction of the Use of Certain Hazardous Substances in Electrical and Electronic Equipment 2002/95/EC (commonly referred to as the Restriction of Hazardous Substances Directive or RoHS) was adopted in February 2003 by the European Union. The state of California has passed a similar law. The directive restricts the use of six hazardous materials in the manufacture of various types of electronic and electrical equipment. The six hazardous materials include Lead, Mercury, Cadmium, Hexavalent chromium (Cr-VI or Cr6+), Polybrominated biphenyls (PBB), and Polybrominated diphenyl ether (PBDE).
Industry seeks efficient and economical measures to comply with RoHS. Dissolution in acid is commonly used to test and measure compositional qualities of sample material. This method has inherent disadvantages. Laser induced breakdown optical emission spectroscopy (LIBS) as well as other laser spectrometry methods are potentially efficient and economical techniques to determining and/or verify the composition of products and other materials.
The LIBS type of spectrometry has been an unreliable and inexact measurement system since there is a large variation in the recorded data. A factor is the inconsistent plasma plume created by the pulse laser. Former LIBS type analyses have been unsuccessful in matching known standards achieved with other analysis methods.